<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<style>
  .box {
    background-color: pink;
    width: 100%;
    height: 200px;
  }

  .inner {
    float: left;
    background-color: red;
    width: 100px;
    height: 100px;
    border: 2px solid white;
  }
</style>
<script src="./vue.js"></script>

<body>
  <div id="app">
    <div v-bind:class="box">
      I am Box
      <div v-bind:class="inner">I am inner one</div>
      <div v-bind:class="inner">I am inner two</div>
    </div>
  </div>
  <script>
    const vm = new Vue({
      el: "#app",
      data: {
        box: "box",
        inner: "inner"
      },
    })
  </script>
</body>

</html>